Materials for lithophane

I've used Corian to do a lithophane but it is hard to buy not to mention expensive.What are the alternative materials that can be used.

Brian

In the some shows I have gone to, ArtCAM had small cameos cut out of 1/8" light gray acrylic.

But haunt some of your local cabinet and counter-top people and you will be able to locate solid surface materials like corian for free or low cost.

Donn

I use plexiglas 1/8 thick part# is 3015 white
works as good and is around $75.00 a sheet 4x8

Acrylic works better when it's a little thicker than .125" Remember that a lithophane is based on contrasting colors of grey so you want something dense enough to give you the darker shades. Anyone who has cut the same lithophane in both 1/8" and "quarter inch" (really.22" I don't care what company you get it from - acrylic is usually a little undersized, must be something they learned from the plywood cartel...) can easily see the difference. Your 1/8" model will be functional, but not nearly as clear/clean as the thicker model...
Corian being denser from the start works very well at it's rated .25" and as Donn points out above some shops will gladly sell/give it to you as long as they realize you aren't trying to go into competition with them. Best solution is usually to MAKE someone at a shop a lithophane, then things get a LOT easier...